Seventy-five patients with chest pain due to prolonged myocardial ischemia (group I, n=45) or acute myocardial infaction (group II, n=30) were treated with continuous intravenous infusion of nitroglycerin. Pain relief was achieved immediately or after titration in 40 of 45 group I patients and 22 of 30 group II patients. Of the 29 group I patients who received narcotic analgesics for pain relief prior to the nitroglycerin infusion, 20 experienced a decrease in narcotics required for pain relief while intravenously receiving nitroglycerin. Twenty-four of 28 group I patients and 14 of 19 group II patients who had angina refractory to multiple doses of sublingual nitroglycerin received relief with intravenous administration of nitroglycerin. This data suggests that intravenous administration of nitroglycerin is useful, adjunctive therapy for chest pain even when refractory to multiple doses of sublingual nitroglycerin.